McGovern attempted to salvage his legislation by demanding a roll-call vote on the 100 or so amendments blocked from a vote during the rules hearing, which began late Wednesday afternoon.

He called the decision to kill his amendment "unconscionable" shortly after the Rules Committee adjourned.

Committee members did, however, approve an amendment by Rep. Barbara Lee (D-Calif.) that would limit Pentagon war spending for Afghanistan to operations supporting "the safe and orderly withdrawal of U.S. troops and military contractors" from the country.

McGovern and Lee appeared at a press conference Wednesday with a group of anti-war lawmakers after sending a letter signed by more than 85 members to President Obama urging him to speed up the Afghan withdrawal.

“This war, if we don’t end it, is endless,” McGovern said at the time. “What we are here to express is our support for any effort on the house floor during the Defense authorization bill that will help accelerate the withdrawal of our troops.”

The McGovern plan was introduced as an amendment to the House version of the fiscal 2013 defense budget bill. It called for the end of all U.S. combat operations by 2013. That is a year ahead of the deadline set by the Obama administration to get all American troops out of Afghanistan.

Smith, the ranking Democrat on the House Armed Services Committee, planned to introduce a similar amendment on the House floor on Thursday. But he dropped those plans in favor of signing on as a co-sponsor to the McGovern amendment.

The Smith amendment would have sped up the U.S. handover of all security operations to Afghan forces. To date, U.S. military leaders have only handed over control of detainee operations and oversight of night raids to the Afghan security forces.

The McGovern plan would also have required the administration "to pursue robust negotiations to address Afghanistan’s and the region’s security and stability."

In March, President Obama and Afghan President Hamid Karzai agreed to a post-war deal that would have all Americans out by 2014, but allow a small number of U.S. special forces to remain in country past that deadline.

Those troops would play an entirely supporting role to the Afghan National Security Forces.

But the McGovern legislation would have required congressional approval of any post-war deployment of American forces.

Additionally, it would have forced the president to explain to Congress "the purpose, cost, number of troops to be deployed, and time frame of mission" of any U.S. military operation in Afghanistan after 2014.